The survey said: 'NHS leaders are seriously concerned about the impact of these pressures on patient safety and mortality.' Photograph: Robert Stainforth/Alamy

Doctors and hospital managers have spoken of their serious fears for the lives of their patients as NHS accident and emergency wards stand on the brink of yet another winter crisis.

In a survey conducted by the NHS Confederation, the body which represents every part of the health service, senior staff said they believed the pressures on their wards will be even worse than last year's difficult winter.

They warn that a 26% jump in admissions among those aged 85 and over in the last four years will cause major problems. Less half of respondents (45.7%) said their hospitals were likely to hit the target of 95% of patients waiting for under four hours before being treated in A&E wards over the next few months.

They add that a prolonged period of cold, a rapid increase in seriously ill patients arriving at A&E or a lengthy norovirus season would be "all it would take to bring many departments to breaking point".

The NHS Confederation report, published on Sunday, said: "One of the starkest findings of our survey was that NHS leaders are seriously concerned about the impact of these pressures on patient safety and mortality.

"Many say the consequences of rising demand could mean a significant increase in cancelled elective surgery; longer waiting times for patients; less time for staff to discuss treatment plans with patients; and serious safety issues, including increased mortality."

Health minister Anna Soubry said an extra £500m had already been set aside for A&E and promised further help. She said: "On Tuesday, we will be setting out exactly how we will be making sure services are fully equipped to deal with additional pressures this year and outlining longer-term changes for the future, including how to better support those with the greatest need – vulnerable older people."

The report comes on the first anniversary of Jeremy Hunt's tenure as health secretary during which, Labour says, close to 1 million patients have waited longer than four hours to be seen in A&E. Official figures show that England's A&E wards have had the worst summer in 10 years. Shadow health secretary Andy Burnham said: "Warnings do not come more serious than this. David Cameron has left A&E on the brink of a serious crisis. We are already in the middle of the worst year in A&E for a decade and now it looks like the coming winter could be even worse. The government's response to date has been woefully inadequate to the scale of the problem."

The NHS Confederation report said staff have despaired of the standard of debate about the crisis in A&E over the past year. Rather than failings in GP contracts or the NHS 111 helpline, it is the impact of an ageing population twinned with under-resourced social care that must take much of the blame, they say.

Mike Farrar, chief executive of the NHS Confederation, called for a more responsible debate about health services. He said: "We have known for some time that pressures on A&E are at their highest ever, and the honest picture is one of a service facing unprecedented demand.

"But as if the genuine rise in seriously ill, frail A&E attendees wasn't putting enough strain on the system, the NHS is also struggling from ill-informed speculation about what is causing the pressures and what services they can rely on to meet their needs.

"The knock-on effect is that the public have so little confidence in alternative options for meeting their healthcare needs that they believe the only recourse is to turn up at A&E. It's a vicious spiral."